The purpose of this research to analyzed exchange rate rupiah to US $, inflation rate, SBI rate and Jumlah Uang Beredar/JUB (M1) to Net Interest Margin (NIM) of Bank Umum period 2006-2009. It used the secondary data from Statistik Ekonomi Keuangan Indonesia (SEKI) which published by Bank Indonesia monthly. The samples took from Net Interest Margin (NIM) of Bank Umum as series, inflation rate, exchange rate rupiah to US $, SBI rate and JUB with period 2006-2009. The method of analysis was descriptive and inferential statistic. The result shows the JUB is not significant influence to Net Interest Margin (NIM) of Bank Umum. The exchange rate rupiah to US $, inflation rate, SBI rate show as positive significant influence to NIM Bank Umum. The exchange rate rupiah to US $ have dominant variable to NIM Bank Umum. As the simultaneous, the four variables have positive significant influence to the Bank Mandiri stock price it can be proofed F value > F table (12.215 > 2.589). And all of the independence variables have influence as 52 percent to NIM Bank Umum.